1. Field of the Invention
The present invention relates to an imaging device and a time-lapse imaging method and, particularly, to time-lapse imaging using an imaging device comprising a pan and tilt mechanism.
2. Description of the Related Art
Conventionally, an imaging device capable of capturing still images at certain imaging intervals (time-lapse imaging), connecting a plurality of captured still images, and recording the connected still images as a time-lapse video is known. Accordingly, a time-lapse video in which changes in a subject over a long period of time, such as a flow of clouds or flowering of a flower, are compressed into a short time can be enjoyed.
Further, an imaging device having a time-lapse imaging function is also applied to an image acquisition device for a microscope that images temporal changes in living cells (JP2004-233664A and JP2011-237818A).
In a case in which temporal changes in living cells are imaged by an image acquisition device for a microscope, fluorescence imaging is generally used, but in this fluorescence imaging, long time exposure in which an exposure time is from a few seconds to tens of seconds may be performed in order to image a very low luminance subject.
Therefore, contradiction may occur in that the exposure time becomes longer than an imaging interval designated by an operator, whereas, in a case in which a time obtained by adding the exposure time to the imaging interval designated by the operator is used as an actual imaging interval, there are problems in that the actual imaging interval may be significantly different from an imaging interval intended by the operator, and subject imaging as desired by the operator cannot be performed.
A microscopic image acquisition device comprising a time-lapse imaging function described in JP2004-233664A is characterized in that the microscopic image acquisition device determines contradiction of time-lapse imaging conditions in a case in which settings regarding imaging such as an exposure time, an imaging interval, and the number of captured images are performed by the operator, and presents the contradiction of the time-lapse imaging conditions based on a result of the determination.
Further, the microscope system has a shallow focal depth. Accordingly, in a case in which an observation sample (a sample having a nucleus sealed with a glass slide and a cover glass) is placed on a stage, and observation of the nucleus is performed, there is a problem in that a motion of the nucleus cannot be observed for a long time if the nucleus is moved above a focus depth area or a focal position of an objective lens is shifted with a change in ambient temperature.
In the microscope system described in JP2011-237818A, an observer is allowed to register a center position of an imaging area, an imaging area (an upper limit of the imaging area and a lower limit of the imaging area) based on the center position of the imaging area, an interval (Z interval) at which a stage is moved in an optical axis direction (Z axis direction), the number of captured images, a time-lapse interval, and an imaging time using a display unit that displays a sample image, an operation display unit regarding control of a microscope, and a display unit that sets imaging conditions of the sample image. If imaging is started after the registration, the microscope system performs imaging of the sample while moving the stage in the optical axis direction (Z axis direction) at the set Z interval from the upper limit of the imaging area to the lower limit of the imaging area, and repeatedly performs this imaging until the imaging time ends, at set time-lapse intervals.
Further, in JP2011-237818A, it is described that, in order to image a plurality of observed bodies (nucleus) within a sample, the observer moves the stage in X and Y directions perpendicular to the optical axis direction through a button operation, determines the plurality of observed bodies on which time-lapse observation is performed, moves the stage at Z intervals in a Z direction, and images the nucleus, and also moves the stage in the X and Y-direction and performs imaging of the plurality of observed bodies.
Meanwhile, there is an imaging device (surveillance camera system) comprising a pan and tilt mechanism, which is a system for performing surveillance while cyclically moving to registered preset positions (specific imaging positions) when pan and tilt positions, a zoom magnification, or the like is registered for preset positions (JP2012-19285A).